U.S. patent application number 15/133759 was filed with the patent office on 2016-08-11 for current detection device, its manufacturing method, and its mounting structure.
This patent application is currently assigned to KOA CORPORATION. The applicant listed for this patent is KOA CORPORATION. Invention is credited to Masakazu Ito, Kenji Kameko, Keishi Nakamura.
Application Number | 20160231359 15/133759 |
Document ID | / |
Family ID | 52992705 |
Filed Date | 2016-08-11 |
United States Patent
Application |
20160231359 |
Kind Code |
A1 |
Nakamura; Keishi ; et
al. |
August 11, 2016 |
CURRENT DETECTION DEVICE, ITS MANUFACTURING METHOD, AND ITS
MOUNTING STRUCTURE
Abstract
Provided is a current detection device, which is capable of
measuring a large current with a high degree of accuracy and
reliability. The current detection device comprises a first wiring
member consisting of a highly conductive material, a second wiring
member consisting of a highly conductive material, and a resistance
body consisting of a metal material having a smaller temperature
coefficient of resistance than the highly conductive materials used
in the wiring members. The first wiring member and the second
wiring member are welded to the resistance body, and the second
wiring member is longer than the first wiring member. The second
wiring member has a plurality of bent portions. The plurality of
bent portions includes portions bent to horizontal direction and
portions bent to vertical direction. Voltage detection terminals
are formed in the vicinity of the resistance body on the first and
second wiring members.
Inventors: |
Nakamura; Keishi; (Ina-shi,
JP) ; Ito; Masakazu; (Ina-shi, JP) ; Kameko;
Kenji; (Ina-shi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOA CORPORATION |
Ina-shi |
|
JP |
|
|
Assignee: |
KOA CORPORATION
Ina-shi
JP
|
Family ID: |
52992705 |
Appl. No.: |
15/133759 |
Filed: |
April 20, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2014/076535 |
Oct 3, 2014 |
|
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|
15133759 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01R 19/0092 20130101;
G01R 1/203 20130101; G01R 15/146 20130101 |
International
Class: |
G01R 15/14 20060101
G01R015/14; G01R 19/00 20060101 G01R019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 25, 2013 |
JP |
2013-222556 |
Claims
1. A current detection device comprising: a first wiring member
consisting of a highly conductive material, a second wiring member
consisting of a highly conductive material, and a resistance body
consisting of a metal material having a smaller temperature
coefficient of resistance than the highly conductive materials used
in the wiring members, wherein the first wiring member and the
second wiring member are welded to the resistance body, and the
second wiring member is longer than the first wiring member.
2. The device of claim 1, wherein the second wiring member has a
plurality of bent portions.
3. The device of claim 2, wherein the plurality of bent portions
includes portions bent to horizontal direction and portions bent to
vertical direction.
4. The device of claim 1, wherein voltage detection terminals are
formed in the vicinity of the resistance body on the first and
second wiring members.
5. The device of claim 1, wherein a nonconductive protective film
is formed on the first wiring member, the resistance body, and the
second wiring member.
6. The device of claim 5, wherein the first wiring member and the
second wiring member are provided with holes, and peripheral areas
of the holes are surface treated by a plated film.
7. A method for manufacturing a current detection device
comprising: preparing a first wiring member consisting of a metal
material, a second wiring member consisting of a metal material,
and a resistance body consisting of a metal material having a
smaller temperature coefficient of resistance than the highly
conductive materials used in the wiring members; making the first
wiring member welded to the resistance body: making the second
wiring member, which is longer than the first wiring member, to
have a plural of bent portions toward a horizontal direction and/or
a vertical direction; and welding the second wiring member to the
resistance body.
8. The method of claim 7, further comprising: forming voltage
detection terminals in the vicinity of the resistance body on the
first and second wiring members.
9. A mounting structure of a current detection device, said device
comprising: a first wiring member consisting of a highly conductive
material, a second wiring member consisting of a highly conductive
material, and a resistance body consisting of a metal material
having a smaller temperature coefficient of resistance than the
highly conductive materials used in the wiring members, wherein the
second wiring member is longer than the first wiring member, and
the second wiring member has a plurality of bent portions, and
wherein both ends of the first wiring member and the second wiring
member are directly connected between devices for detecting a
current flowing therethrough.
10. The mounting structure of claim 9, wherein the plurality of
bent portions includes portions bent to horizontal direction and
portions bent to vertical direction.
11. The mounting structure of claim 9, wherein voltage detection
terminals are formed in the vicinity of the resistance body on the
first and second wiring members.
Description
TECHNICAL FIELD
[0001] The present invention relates to a current detection device,
and particularly relating to the device, which is capable of
measuring a large current with a high degree of accuracy while
using the device as a wiring for supplying a current.
BACKGROUND ART
[0002] Current detections are adopted for detecting a charge and
discharge current in a battery, for detecting a motor current for
driving electric motor vehicles and hybrid motor vehicles, for
detecting a current in electric equipment such as air conditioner,
solar cell system or so on. The current is detected by measuring a
voltage between both ends of resistance body of the shunt resistor
caused by the current flowing therethrough.
[0003] Busbars are selected as a route of a path for supplying a
current from a power source such as battery to an electrical
equipment. A shunt resistor might be connected to the busbar for
detecting a current flowing through the busbar. In the cases, the
busbar and the shunt resistor might be connected by screw stop or
by soldering. (see Japanese laid open patent publication 2011-3694
and H6-224014 etc.)
[0004] However, those connection methods increase connection
portions, which become a factor of a heat generation. The methods
may cause a problem of securing connection reliability. Therefore,
a current detection device, which can use for detecting a large
current with high reliability, is desired.
[0005] Forming a shunt resistor at a portion inside of a busbar is
proposed by forming a long hole at the portion (see Japanese laid
open patent publication 2001-349907). However, as to the busbar, a
metal of low resistivity such as copper is generally used. The
metal such as copper has high resistance temperature coefficient,
then it is difficult to detect a current with high accuracy.
Therefore highly accurate current detection is difficult for
forming a shunt resistor portion inside of the busbar with using
the metal material such as copper for the portion.
SUMMARY OF INVENTION
Technical Problem
[0006] The invention has been made basing on above-mentioned
circumstances. Therefore an object of the invention is to provide a
current detection device, its manufacturing method, and its
mounting structure, which can measure a current flowing through a
busbar with high accuracy and with high reliability.
Solution to Problem
[0007] The current detection device of the invention comprises a
first wiring member consisting of a highly conductive material, a
second wiring member consisting of a highly conductive material,
and a resistance body consisting of a metal material having a
smaller temperature coefficient of resistance than the highly
conductive materials used in the wiring members, wherein the first
wiring member and the second wiring member are welded to the
resistance body, and the second wiring member is longer than the
first wiring member.
[0008] The manufacturing method of the current detection device of
the invention comprises preparing a first wiring member consisting
of a metal material, a second wiring member consisting of a metal
material, and a resistance body consisting of a metal material
having a smaller temperature coefficient of resistance than the
highly conductive materials used in the wiring members, the first
and second wiring members being more highly conductive than the
resistance body, and welding the first and second wiring members to
the resistance body. The first wiring member is a shorter one, and
can be standardized as a semifinished product with the resistance
body so as to be easy for mass production. The second wiring member
is a longer one, and having a plurality of bent portions, which are
bent to horizontal and/or vertical directions. The second wiring
member is formed so as to be matching with users specifications.
Then both ends of the busbar consisting of the first wiring member,
the resistance body, and the second wiring member can be directly
connected between devices for detecting a current flowing
therethrough.
[0009] According to the invention, because both ends of the
resistance body are strongly fixed to the wiring members, the
function of the bus bar can be integrated with the function of the
shunt resistor, and the connections become unnecessary. Therefore
the number of parts can be decreased, the mounting cost can be
decreased, and the connection reliability can be improved. Because
the resistance body consisting of metal material having a small
resistance temperature coefficient is built in the bus bar,
detection of a large current with high accuracy becomes possible as
well as the shunt resistor. Thus above mentioned problems have been
solved.
[0010] Because the second wiring member is a longer one, it becomes
possible to make the wiring member a complicated bent shape. That
is, it becomes possible to make the structure of the wiring member
being matched with user's specifications. The first wiring member
is a shorter one, and can be standardized as a semifinished product
with the resistance body. Therefore a part including the first
wiring member and the resistance body has high mass productivity
and a part including the second wiring member has enhanced custom
designability. Thus coexisting of mass productivity and custom
designability becomes possible. Further by forming a plurality of
bent portions in the second wiring member, it becomes possible to
ease concentration of stress to welded portions of the resistance
body and the wiring member.
BRIEF DESCRIPTION OF DRAWINGS
[0011] FIG. 1 shows a perspective view of a current detection
device of first embodiment of the invention.
[0012] FIG 2 Upper part of FIG. 2 shows a plan view of FIG. 1,
lower left part of FIG. 2 shows a front view of FIG 1, and lower
right view of FIG. 2 shows a side view of FIG. 1.
[0013] FIG. 3 shows a perspective view of a current detection
device of second embodiment of the invention.
[0014] FIG. 4 Upper part of FIG. 4 shows a plan view of FIG. 3, and
lower part of FIG. 4 shows a front view of FIG. 3.
[0015] FIG. 5 shows a perspective view of a current detection
device of third embodiment of the invention.
[0016] FIG. 6 shows a perspective view of a current detection
device of fourth embodiment of the invention.
[0017] FIG. 7 shows a perspective view of a current detection
device of fifth embodiment of the invention.
[0018] FIG. 8 shows a perspective view of voltage detection
terminals of another embodiment of the invention.
DESCRIPTION OF EMBODIMENTS
[0019] Embodiments of the invention will be described below with
referring to FIG. 1 through FIG. 8. Like or corresponding parts or
elements will be denoted and explained by same reference characters
throughout views.
[0020] FIGS. 1 and 2 show a current detection device of first
embodiment, which measures a current flowing through the busbar. A
resistance body 13 is welded and fixed between first wiring member
11 and second wiring member 12, which is longer than first wiring
member 11. That is, the current detection device builds in the
shunt resistor (resistance body) 13 between the wiring members 11,
12. And the whole structure of the current detection device
consists of a busbar.
[0021] The first and second wiring members 11,12 are strip
(busbar)-shaped highly conductive metal material consisting of
copper, copper system alloy, or aluminum etc. "Highly conductive"
means that electroconductivity is high, and that conductivity of
wiring members are higher than conductivity of resistance body 13.
The resistance body 13 consists of metal resistance alloy material
such as Cu--Mn system alloy, Cu--Ni system alloy, or Ni--Cr system
alloy, which has extremely lower resistance temperature coefficient
than metal material such as copper etc.
[0022] Both end faces of the resistance body 13 are abutted and
welded to end faces of the wiring members 11,12, and strongly
bonded surfaces are formed. The welding may use electron beam
welding, laser beam welding, brazing or soldering, etc. Further,
pressure bonding may be used by contacting end faces of resistance
body and wiring members and pressurizing to be bonded.
[0023] A pair of voltage detection terminals 14,15 is installed in
the wiring member 11,12 near the resistance body 13. The current
flowing through the wiring member 11,12 flows through the
resistance body 13, and the voltage caused at th ends of the
resistance body 13 is detected by voltage detection terminals
14,15. That is, because the wiring members carry out the function
of the electrodes or the terminals of shunt resistors, the function
of shunt resistors can be integrated with the function of the
busbar. Then connection portion between a shunt resistor and a
busbar becomes unnecessary, and number of parts can be decreased.
Thus, the current flowing through the busbar can be measured with
high accuracy and high reliability.
[0024] The second wiring member 12 is longer than the first wiring
member 11. The second wiring member 12 has a plural of bent
portions as shown in FIG. 1. A bent portion 16 is bent in a
horizontal plane, and a bent portion 17 is bent from a horizontal
plane to a vertical plane. And a bent portion 18 is bent from a
vertical plane to a horizontal plane.
[0025] Because the longer wiring member 12 has a plural of bent
portions 16, 17, 18, the wiring member 12 can be formed to adapt to
custom design bent shapes according to user's specifications. Thus
the equipment, which installs the wiring member 12, can be made to
small and compact. Further by forming a plural of bent portions in
the wiring member, a stress applied to the busbar can be dispersed.
Further a stress applied to junction surfaces between resistance
body 13 and wiring members 11,12 can be decreased.
[0026] Because both ends of wiring members 11,12 have holes 19,20,
both ends of the busbar having the shunt resistor function (that
is, the current detection device) can be directly connected between
devices for detecting a current flowing therethrough with bolt
fixing etc. "Between devices for detecting a current flowing
therethrough" includes "between a battery and a chassis ground for
detecting a current flowing therethrough", "between a battery and
an inverter device for detecting a current flowing therethrough",
or so on.
[0027] According to prior art technology, a pair of devices for
detecting a current flowing therethrough is connected with a serial
connection of a shunt resistor and a busbar or a wiring. However,
according to the invention, the pair of devices is connected
therebetween with only the current detection device for detecting a
current flowing therethrough. That is, the mounting structure of
the invention can save the number of parts, decrease the mounting
cost, and increase the connection reliability. Further without
having the holes 19,20, both ends of the busbar having the shunt
resistor function can be connected between the devices with welding
etc.
[0028] The second wiring member 12 is longer than the first wiring
member 11, and long current detection device like a busbar is
realized as a whole. The resistance body 13 is positioned near one
of the devices, to detect the current because the first wiring
member 11 is short. Then heat generation at the resistance body 13
can be easily absorbed into one of the devices.
[0029] By making the first wiring member 11 a shorter one, the
first wiring member 11 including the resistance body 13 can be
standardized, then manufacturing process for mass production
becomes easy. By making the second wiring member 12 a longer one,
it becomes possible to make the second wiring member a complicated
bent shape. That is, it becomes possible to make the structure of
the second wiring member being adapted to user's specifications.
Thus, as to the busbar having the current detection function, the
coexisting of mass productivity and the custom designability
becomes possible.
[0030] FIGS. 3 and 4 show a current detection device, which
measures a current flowing through the busbar, according to the
second embodiment. It is common with the first embodiment that the
resistance body 13 is welded and connected between the first wiring
member 11 and the second wiring member 12. In the embodiment,
though a straight wiring member may be able to connect from hole 19
to hole 20, the wiring member 12 is made to a detour downward by
installing bent portions 21,22,23,24 corresponding to user's
specifications. Therefore, a small and compact design of the
equipment becomes possible for the users, and the number of the
parts can be reduced.
[0031] FIG. 5 shows a current detection device, which measures a
current flowing through the busbar, according to the third
embodiment. In the embodiment, the wiring member 12 is made to a
detour on a side in the horizontal plane by installing bent
portions 25,26,27,28 according to users specifications. Therefore,
a small and compact design of the equipment becomes possible for
the users, and the number of the parts can be reduced.
[0032] FIG. 6 shows a current detection device, which measures a
current flowing through the busbar, according to the fourth
embodiment. In the embodiment, bent portions 29,30,31, 32,33 are
installed. The wiring member 12 is made to be bent at portion 29
from resistance body 13 side in horizontal plane to downward
vertically, making a detour downward. The wiring member 12 is bent
to horizontal direction at portion 30, is bent to vertical
direction in a horizontal plane making a detour on a side in the
horizontal plane at portion 31, is bent to vertical direction in
the vertical plane at portion 32, and is bent to horizontal
direction at portion 33.
[0033] Therefore, a small and compact design of the equipment
becomes possible for the users, and the number of the parts can be
reduced. The current detection device is formed to have bent
portions, which detour obstacles, so as to attain compact
design.
[0034] FIG. 7 shows a current detection device, which measures a
current flowing through the busbar, according to the fifth
embodiment. Entire surfaces of the wiring members 11,12 and the
resistance body 13 is covered by a protective film 35 except holes
19,20 and their peripherals. Only voltage detection terminals 14,15
are projected from the protective film 35. Peripheral areas of hole
19,20, which are not covered by the protective film, are surface
treated by plated film 36,37 such as Sn or Ni etc.
[0035] The entire busbar can be prevented from being oxidized by
covering with protective film 35 and plated films 36,37. As to
protective film 35, a nonconductive protective film, for example,
coated film of inorganic material such as glass or ceramics etc. or
nonconductive oxide film formed by alumite treatment etc. can be
used.
[0036] According to the current detection devices as shown in FIGS.
1 through 7, all of the wiring member 11 and the resistance body 13
has same standardized common structure. Thus the wiring member 11
and the resistance body 13 or an intermediate member consisting of
wiring member 11 and resistance body 13 being connected can be
manufactured and stocked. When the wiring member 12, which is
formed basing on users specification, is welded to the stocked
parts, then finished product of the current detection device can be
obtained. Efficiency of manufacturing the current detection device
improves, and the current detection device having various shapes
can be manufactured.
[0037] According to above embodiments, voltage detection terminals
are projected on a surface of the wiring member vertically.
However, voltage detection terminals 14,15 may be installed at
vicinity of joint surface with resistance body on wiring members,
and then constructions shown in FIG. 8 are possible. That is, left
view in FIG. 8 shows that voltage detection terminals 14a,15a are
projected on side surfaces of wiring members horizontally. Also,
right view in FIG. 8 shows that installing cuts 38,39 in neighbor
of joint surface with resistance body on wiring members, and making
the portions between the cut and joint surface used as voltage
detection terminals 14b,15b.
[0038] Although embodiments of the invention have been explained,
however the invention is not limited to above embodiments, and
various changes and modifications may be made within scope of the
technical concepts of the invention.
INDUSTRIAL APPLICABILITY
[0039] The invention can be suitably used for the current detection
devices, which measure large currents flowing through the wiring
members.
* * * * *